<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>绝对定位方法</title>
	<style>
		html,body{
			margin:0;
			padding: 0;
		}
		.box{
			width: 500px;
			height: 350px;
			background: #c00;
			border: 1px solid #888;
			position: absolute;
			top: 0;
			left: 0;
			bottom: 0;
			right: 0;
			margin: auto;
		}
	</style>
</head>
<body>
	<div class="box">
		<div class="small">
			Lorem ipsum dolor sit amet, consectetur adipisicing elit. Dolores ipsum facilis voluptatibus non rerum explicabo tempora blanditiis optio, suscipit at, placeat harum itaque maiores vitae nobis commodi illo, esse accusantium.
		</div>
	</div>
</body>
</html>